mempool: Support mempool address and size alignment by setting CONFIG_MM_NODE_GUARDSIZE

Setting a reasonable CONFIG_MM_NODE_GUARDSIZE can ensure absolute alignment of usersize

Signed-off-by: wangmingrong1 <[email protected]>

Author: W-M-R

mm/mempool/mempool.c

@@ -40,6 +40,8 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+#define MEMPOOL_HEADER_SIZE (sizeof(sq_entry_t) + CONFIG_MM_NODE_GUARDSIZE)
+
 #if CONFIG_MM_BACKTRACE >= 0
 #define MEMPOOL_MAGIC_FREE  0x55555555
 #define MEMPOOL_MAGIC_ALLOC 0xAAAAAAAA
@@ -148,7 +150,7 @@ static void mempool_foreach(FAR struct mempool_s *pool,
 
   sq_for_every(&pool->equeue, entry)
     {
-      nblks = (pool->expandsize - sizeof(sq_entry_t)) / blocksize;
+      nblks = (pool->expandsize - MEMPOOL_HEADER_SIZE) / blocksize;
       base = (FAR char *)entry - (nblks * blocksize);
 
       while (nblks--)
@@ -280,10 +282,11 @@ int mempool_init(FAR struct mempool_s *pool, FAR const char *name)
       pool->ibase = NULL;
     }
 
-  if (pool->initialsize >= blocksize + sizeof(sq_entry_t))
+  if (pool->initialsize >= blocksize + MEMPOOL_HEADER_SIZE)
     {
-      size_t ninitial = (pool->initialsize - sizeof(sq_entry_t)) / blocksize;
-      size_t size = ninitial * blocksize + sizeof(sq_entry_t);
+      size_t ninitial = (pool->initialsize - MEMPOOL_HEADER_SIZE) /
+                        blocksize;
+      size_t size = ninitial * blocksize + MEMPOOL_HEADER_SIZE;
       FAR char *base;
 
       base = pool->alloc(pool, size);
@@ -363,11 +366,11 @@ FAR void *mempool_allocate(FAR struct mempool_s *pool)
           size_t blocksize = MEMPOOL_REALBLOCKSIZE(pool);
 
           spin_unlock_irqrestore(&pool->lock, flags);
-          if (pool->expandsize >= blocksize + sizeof(sq_entry_t))
+          if (pool->expandsize >= blocksize + MEMPOOL_HEADER_SIZE)
             {
-              size_t nexpand = (pool->expandsize - sizeof(sq_entry_t)) /
+              size_t nexpand = (pool->expandsize - MEMPOOL_HEADER_SIZE) /
                                blocksize;
-              size_t size = nexpand * blocksize + sizeof(sq_entry_t);
+              size_t size = nexpand * blocksize + MEMPOOL_HEADER_SIZE;
               FAR char *base = pool->alloc(pool, size);
 
               if (base == NULL)
@@ -499,7 +502,7 @@ int mempool_info(FAR struct mempool_s *pool, FAR struct mempoolinfo_s *info)
   info->ordblks = sq_count(&pool->queue);
   info->iordblks = sq_count(&pool->iqueue);
   info->aordblks = pool->nalloc;
-  info->arena = sq_count(&pool->equeue) * sizeof(sq_entry_t) +
+  info->arena = sq_count(&pool->equeue) * MEMPOOL_HEADER_SIZE +
     (info->aordblks + info->ordblks + info->iordblks) * blocksize;
   spin_unlock_irqrestore(&pool->lock, flags);
   info->sizeblks = blocksize;
@@ -620,16 +623,16 @@ int mempool_deinit(FAR struct mempool_s *pool)
       return -EBUSY;
     }
 
-  if (pool->initialsize >= blocksize + sizeof(sq_entry_t))
+  if (pool->initialsize >= blocksize + MEMPOOL_HEADER_SIZE)
     {
-      count = (pool->initialsize - sizeof(sq_entry_t)) / blocksize;
+      count = (pool->initialsize - MEMPOOL_HEADER_SIZE) / blocksize;
     }
 
   if (count == 0)
     {
-      if (pool->expandsize >= blocksize + sizeof(sq_entry_t))
+      if (pool->expandsize >= blocksize + MEMPOOL_HEADER_SIZE)
         {
-          count = (pool->expandsize - sizeof(sq_entry_t)) / blocksize;
+          count = (pool->expandsize - MEMPOOL_HEADER_SIZE) / blocksize;
         }
     }
 
@@ -641,11 +644,11 @@ int mempool_deinit(FAR struct mempool_s *pool)
     {
       blk = (FAR sq_entry_t *)((FAR char *)blk - count * blocksize);
 
-      blk = kasan_unpoison(blk, count * blocksize + sizeof(sq_entry_t));
+      blk = kasan_unpoison(blk, count * blocksize + MEMPOOL_HEADER_SIZE);
       pool->free(pool, blk);
-      if (pool->expandsize >= blocksize + sizeof(sq_entry_t))
+      if (pool->expandsize >= blocksize + MEMPOOL_HEADER_SIZE)
         {
-          count = (pool->expandsize - sizeof(sq_entry_t)) / blocksize;
+          count = (pool->expandsize - MEMPOOL_HEADER_SIZE) / blocksize;
         }
     }